On Wed, Nov 9, 2016 at 3:19 PM, Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> wrote: > On systems booting with a device tree, every struct device is associated > with a struct device_node, that provides its DT firmware representation. > The device node can be used in generic kernel contexts (eg IRQ > translation, IOMMU streamid mapping), to retrieve the properties > associated with the device and carry out kernel operations accordingly. > Owing to the 1:1 relationship between the device and its device_node, > the device_node can also be used as a look-up token for the device (eg > looking up a device through its device_node), to retrieve the device in > kernel paths where the device_node is available. > > On systems booting with ACPI, the same abstraction provided by > the device_node is required to provide look-up functionality. > > The struct acpi_device, that represents firmware objects in the > ACPI namespace already includes a struct fwnode_handle of > type FWNODE_ACPI as their member; the same abstraction is missing > though for devices that are instantiated out of static ACPI tables > entries (eg ARM SMMU devices). > > Add a new fwnode_handle type to associate devices created out > of static ACPI table entries to the respective firmware components > and create a simple ACPI core layer interface to dynamically allocate > and free the corresponding firmware nodes so that kernel subsystems > can use it to instantiate the nodes and associate them with the > respective devices. > > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> > Reviewed-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx> > Tested-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx> > Tested-by: Tomasz Nowicki <tn@xxxxxxxxxxxx> > Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> Thanks! -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
